How to eliminate duplicates from an array?




Answers were Sorted based on User's Feedback



Answer / manju

by using HashSet(Collection name)

Is This Answer Correct ?    33 Yes 1 No

Answer / edward sudhaharchennai

Unlike other implementations of the collection interface,
implementation of the Set intrface do not allow duplicate
elements. This also means that a set can contain at most
one null value. The set interface does not define any new
methods, and its add() and addAll() methods will not store
duplicates. If an element is not currently in the set, two
consecutive calls to the add() method to insert the element
will first return true then false...........

Is This Answer Correct ?    6 Yes 2 No

Answer / gajendra

using hash map or treeset of collection framework

Is This Answer Correct ?    8 Yes 5 No




Answer / qim2010

Using HashSet class we can eliminate duplicates from and
array. Here is a simple example

public class ArrayRemoveDuplicate {
public static void main(String[] args) {
//
// A string array with duplicate values
//
String[] data = {"A", "C", "B", "D", "A", "B", "E",
"D", "B", "C"};
System.out.println("Original array : " +
Arrays.toString(data));

//
// Convert it to list as we need the list object to
create a set object.
// A set is a collection object that cannot have a
duplicate values, so
// by converting the array to a set the duplicate
value will be removed.
//
List<String> list = Arrays.asList(data);
Set<String> set = new HashSet<String>(list);

System.out.print("Remove duplicate result: ");

//
// Create an array to convert the Set back to array.
The Set.toArray()
// method copy the value in the set to the defined
array.
//
String[] result = new String[set.size()];
set.toArray(result);
for (String s : result) {
System.out.print(s + ", ");
}
}
}

Is This Answer Correct ?    4 Yes 1 No

Answer / vijaya bhaskar teegala

use linkedHashSet.It will maintain the insertion order

Is This Answer Correct ?    1 Yes 1 No

Answer / elango boopathy

package com.sample.pack;

import java.util.ArrayList;
import java.util.List;

public class Duplicates {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
int k = 1;
String[] str = { "abc", "123", "tyu", "xyz", "123", "m",
"abc", "abc" };
boolean isDuplicate = false;
List<String> list = new ArrayList<String>();

for (int i = 0; i < str.length; i++) {
for (int j = k; j < str.length; j++) {
if (str[i].equals(str[j].toString())) {
isDuplicate = true;
}
}
k = k + 1;
if(isDuplicate == false){
list.add(str[i]);

}
isDuplicate = false;
}
Object[] afterDuplicate = list.toArray();
for(int i=0; i<afterDuplicate.length; i++){
System.out.println(afterDuplicate[i]);
}
}

}

Is This Answer Correct ?    0 Yes 0 No

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